Question

我试图在pygame中执行拖放式机制，并且我获得了部分成功（感谢this one等问题的答案以及this other one等教程。我使用的机制如下：一旦检测到按下按钮的事件，我在每个循环中更新图像的位置（并且仅当鼠标在图像上方时）。为此，我通过调用image.get_rect（）创建了一个矩形对象，但似乎这个矩形被移动了，图像的中心位于矩形的右下角。我附上了代码和结果：

import pygame, sys
from pygame.locals import *

FPS = 60
fpsClock = pygame.time.Clock()


def main():
    pygame.init()

    DS = pygame.display.set_mode((400, 400), 0, 32)
    pygame.display.set_caption('Drag-n-drop that cat')

    WHITE = (255, 255, 255)
    BLACK = (0, 0, 0)
    catImg = pygame.image.load('cat.png') # I load the image
    catImgRectObj = catImg.get_rect() # I create the rect object
    catx = 200
    caty = 200
    catImgRectObj.center = [catx, caty]
    IsMousePressed = False

    while True:
        lastPos = catImgRectObj.center
        DS.fill(WHITE)
        for event in pygame.event.get():
            if event.type == QUIT:
                pygame.quit()
                sys.exit()
            elif event.type == MOUSEBUTTONDOWN:
                IsMousePressed = True
            elif event.type == MOUSEBUTTONUP:
                IsMousePressed = False

        if IsMousePressed and isMouseOverObj(catImgRectObj):
            catImgRectObj.center = pygame.mouse.get_pos() #I update the center
        else:
            catImgRectObj.center = lastPos

        pygame.draw.rect(DS, BLACK, catImgRectObj) #draw the rect object
        DS.blit(catImg, catImgRectObj.center) #draw the cat.
        pygame.display.update()
        fpsClock.tick(FPS)


def isMouseOverObj(Obj):
    return Obj.collidepoint(pygame.mouse.get_pos())

if __name__ == '__main__':
    main()

Answer 1

使用

DS.blit(catImg, catImgRectObj.center)

而不是

catImgRectObj

画猫。

catImgRectObj.center rect已经描述了猫图像的位置，以及是否使用import pygame, sys from pygame.locals import * FPS = 60 fpsClock = pygame.time.Clock() def main(): pygame.init() DS = pygame.display.set_mode((400, 400), 0, 32) pygame.display.set_caption('Drag-n-drop that cat') catImg = pygame.image.load('cat.png').convert_alpha() catMask = pygame.mask.from_surface(catImg) catImgRectObj = catImg.get_rect(center=(200, 200)) IsMousePressed = False while True: DS.fill(pygame.color.THECOLORS['white']) for event in pygame.event.get(): if event.type == QUIT: pygame.quit() sys.exit() elif event.type == MOUSEBUTTONDOWN and isMouseOverObj(catMask, catImgRectObj): IsMousePressed = True elif event.type == MOUSEBUTTONUP: IsMousePressed = False elif event.type == MOUSEMOTION and IsMousePressed: catImgRectObj.move_ip(event.rel) DS.blit(catImg, catImgRectObj) pygame.display.update() fpsClock.tick(FPS) def isMouseOverObj(mask, rect): mouse_pos = pygame.mouse.get_pos() rel_pos = (mouse_pos[0] - rect.left, mouse_pos[1] - rect.top) return rect.collidepoint(mouse_pos) and mask.get_at(rel_pos) if __name__ == '__main__': main()在屏幕上显示它，但是将其左上角移动到所需区域的中心。

另外，我会用这样的东西：

//assume user does not want to continue.
boolean continue = false;
do
{
//process whatever you want

//ask the user
Prompt= JOptonPane.showInputDialog(null,proString,HEADING,JOptionPane.QUESTION_MESSAGE);
input = char.parseChar(Prompt);
//wait until you get a valid input
while(input != "y"||"n")
{
JOptionPane.showMessageDialog(null,"Invalid Input", "Error",JOptionPane.INFORMATION_MESSAGE);
Prompt= JOptonPane.showInputDialog(null,proString,HEADING,JOptionPane.QUESTION_MESSAGE); 
input = char.parseChar(Prompt);
}
//if user wants to continue, change your flag to true
if(input == "y") {
    continue = true;
}
//otherwise make it false
else if(input == "n") {
    continue = false;
}
while(continue); //if continue is true loop back

使碰撞检测像素完美，简化代码，并在点击猫时防止跳。

图像上的get_rect（）在pygame

1 个答案: